The result of combining the words 'what' and 'you' in any combination. Commonly used by puerto ricans who try to lessen the amount of syllables and words in a given sentence by rolling them up into one.
what are you doing? becomes "chu doin'?"
what are you saying? becomes "chu sayin'?"
what did you say? becomes "chu say?" usually followed by a noun of some sort, "chu say fool?"
what do you want? becomes "chu want?"
and so on...